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ABSTRACT: Actions of many herbal medicine products for cancer treatment are linked to an altered production of TGF-β in the target cells. An altered TGF-β production in the target cells will have profound effects on the patients. Therefore, it is important that we review the pros and cons of these products on cancer development and progression in terms of TGF-β signaling. It has been well established that TGF-β is growth inhibitory to benign cells or early stages of cancer cells but it is tumor promoting and metastatic for advanced malignancies. Further, many dietary components can alter gene-specific DNA methylation levels in systemic and in target tissues. Since TGF-β signaling in cancer is closely linked to the DNA methylation profiles, we also review the effect of dietary components on DNA methylation. In light of this knowledge, it is important to note that many natural products that can induce TGF-β production in the target cells may be beneficial in preventing cancer development but may be harmful for cancer patients, especially when they harbor advanced stage cancer. A discussion of the effect of herbal natural products on cancer can be divided into Three categories. The first category of herbal medicine products will be those related to the induction of cancer as far as TGF-β is concerned. Since TGF-β is growth inhibitory and pro-apoptosis to benign cells, any herbal medication that can induce the production of TGF-β in the target cells will be beneficial to the patients. However, such herbal medicine may not necessarily be beneficial to patients with established and advanced cancer. The second category of herbal products will inhibit TGF-β signaling and will reduce TGF-β mediated growth promotion and metastasis in advanced cancers. For patients with established and advanced cancer, agents that can inhibit the production of TGF-β may also inhibit cancer growth and metastasis. Finally, the third category of herbal products have no impact on TGF-β signaling, such as lycopene.
Current cancer drug targets 04/2013; · 5.13 Impact Factor
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Qiang Zhang,
Lin Chen,
Brian T Helfand,
Thomas L Jang,
Vidit Sharma,
James Kozlowski,
Timothy Michael Kuzel,
Lihua J Zhu,
Ximing J Yang,
Borko Javonovic,
Yinglu Guo,
Scott Lonning,
Jay Harper,
Beverly A Teicher,
Charles Brendler,
Nengwang Yu,
William J Catalona, Chung Lee
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ABSTRACT: DNA methyltransferase (DNMT) is one of the major factors mediating the methylation of cancer related genes such as TGF-β receptors (TβRs). This in turn may result in a loss of sensitivity to physiologic levels of TGF-β in aggressive prostate cancer (CaP). The specific mechanisms of DNMT's role in CaP remain undetermined. In this study, we describe the mechanism of TGF-β-mediated DNMT in CaP and its association with clinical outcomes following radical prostatectomy.
We used human CaP cell lines with varying degrees of invasive capability to describe how TGF-β mediates the expression of DNMT in CaP, and its effects on methylation status of TGF-β receptors and the invasive capability of CaP in vitro and in vivo. Furthermore, we determined the association between DNMT expression and clinical outcome after radical prostatectomy. We found that more aggressive CaP cells had significantly higher TGF-β levels, increased expression of DNMT, but reduced TβRs when compared to benign prostate cells and less aggressive prostate cancer cells. Blockade of TGF-β signaling or ERK activation (p-ERK) was associated with a dramatic decrease in the expression of DNMT, which results in a coincident increase in the expression of TβRs. Blockade of either TGF-β signaling or DNMT dramatically decreased the invasive capabilities of CaP. Inhibition of TGF-β in an TRAMP-C2 CaP model in C57BL/6 mice using 1D11 was associated with downregulation of DNMTs and p-ERK and impairment in tumor growth. Finally, independent of Gleason grade, increased DNMT1 expression was associated with biochemical recurrence following surgical treatment for prostate cancer.
Our findings demonstrate that CaP derived TGF-β may induce the expression of DNMTs in CaP which is associated with methylation of its receptors and the aggressive potential of CaP. In addition, DNMTs is an independent predictor for disease recurrence after prostatectomy, and may have clinical implications for CaP prognostication and therapy.
PLoS ONE 01/2011; 6(9):e25168. · 4.09 Impact Factor
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ABSTRACT: To elucidate the mechanism of transforming growth factor (TGF)-β1 overexpression in prostate cancer cells.
Malignant (PC3, DU145) and benign (RWPE1, BPH1) prostate epithelial cells were used. Phosphatase activity was measured using a commercial kit. Recruitment of the regulatory subunit, Bα, of protein phosphatase 2A (PP2A-Bα) by TGF-β type I receptor (TβRI) was monitored by coimmunoprecipitation. Blockade of TGF-β1 signaling in cells was accomplished either by using TGF-β-neutralizing monoclonal antibody or by transduction of a dominant negative TGF-β type II receptor retroviral vector.
Basal levels of TGF-β1 in malignant cells were significantly higher than those in benign cells. Blockade of TGF-β signaling resulted in a significant decrease in TGF-β1 expression in malignant cells, but not in benign cells. Upon TGF-β1 treatment (10 ng/mL), TGF-β1 expression was increased in malignant cells, but not in benign cells. This differential TGF-β1 auto-induction between benign and malignant cells correlated with differential activation of extracellular signal-regulated kinase (ERK). Following TGF-β1 treatment, the activity of serine/threonine phosphatase and recruitment of PP2A-Bα by TβRI increased in benign cells, but not in malignant cells. Inhibition of PP2A in benign cells resulted in an increase in ERK activation and in TGF-β1 auto-induction after TGF-β1 (10 ng/mL) treatment.
These results suggest that TGF-β1 overexpression in malignant cells is caused, at least in part, by a runaway of TGF-β1 auto-induction through ERK activation because of a defective recruitment of PP2A-Bα by TβRI.
Urology 10/2010; 76(6):1519.e8-13. · 2.43 Impact Factor
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ABSTRACT: Human tissue kallikrein 7 (hK7), a chymotrypsin-like secreted serine protease, catalyzes the degradation of intercellular adhesive structures in the cornified layer of the skin, leading to desquamation. Thus, hK7 is implicated in cancer invasion and metastasis. Although hK7 is highly expressed in prostate tissues, its biological role in prostate cancer progression is poorly understood. In the current study, we established an hK7-expressing cell model for prostate tumors by stably transfecting prostate carcinoma 22RV1 and DU145 cells with an expression vector encoding hK7. We found that there were no obvious differences in cell proliferation between cells overexpressing hK7 and cells transfected with empty vector (p>0.05). Intriguingly, a Matrigel invasion assay revealed that hK7 remarkably increased the migration and invasion of prostate cancer cells (p<0.01). Furthermore, hK7 induced epithelial-mesenchymal transition-like changes in prostate carcinoma cells, as evidenced by scattered cellular growth, mesenchyma-like morphology, and up-regulated expression of vimentin, a mesenchymal marker. These novel findings suggest that hK7 plays an important role in mediating prostate cancer progression and that hK7 promotes invasion and metastasis, at least in part, through inducing the epithelial-mesenchymal transition of prostatic carcinoma cells.
Anticancer research 09/2010; 30(9):3413-20. · 1.73 Impact Factor
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ABSTRACT: Castration experiments in rodents show that the stromal vasculature is critical to the androgen-mediated prostate growth regulation. However, the role of angiogenesis inhibitors, such as thrombospondin-1 (TSP-1), in this process is unclear. TSP-1 is a multifunctional glycoprotein that can function as a potent angiogenesis inhibitor and an in vivo activator of latent transforming growth factor-beta (TGF-beta) in some tissues. On the basis of these observations, we hypothesized that TSP-1 regulated androgen withdrawal-induced prostate regression and that this process was mediated not only through antiangiogenic activity but also through TGF-beta activation. To test this, we evaluated angiogenic activity in human prostate epithelial and stromal cells treated with androgens and hypoxia in vitro. TSP-1 knockout mice were characterized to investigate the in vivo functions of TSP-1. In vitro, we found that androgens and hypoxia differentially regulated TSP-1 and angiogenic activity. Androgens stimulated normal epithelial cell, but inhibited normal stromal cell, angiogenic activity. Conversely, hypoxia stimulated stromal while inhibiting epithelial activity. Thus, in vivo, net angiogenic activity must reflect cellular interactions. And, we found that media conditioned by epithelial cells grown under normoxic conditions stimulated stromal cell angiogenic activity, and if epithelial cells were grown under hypoxic conditions, stromal activity was further increased. TSP-1 levels, however, were unchanged. In vivo, TSP-1 loss in a mouse model led to prostate epithelial hyperplasia by 3 months of age with only a modest stromal effect. Androgens suppressed TSP-1 as expression increased after castration both in normal mouse prostate and in human prostate cancer tissues. In addition, TSP-1 expression corresponded to increased TGF-beta activation in mouse tissues, specifically in the stromal compartment. These data show a critical role for TSP-1 in prostate epithelial and stromal growth regulation through angiogenic inhibition and activation of latent TGF-beta. Therefore, loss of TSP-1 during tumorigenesis would eliminate two barriers to cancer progression.
Laboratory Investigation 05/2010; 90(7):1078-90. · 3.64 Impact Factor
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ABSTRACT: Estrogen receptor-related receptor alpha (ERRalpha) is an orphan member of the nuclear receptor superfamily of transcription factors. ERRalpha is highly expressed in the prostate, especially in prostate stromal cells. However, little is known about the regulation and function of ERRalpha, which may contribute to the progression of prostatic diseases. We previously found that prostaglandin E2 (PGE2) up-regulated the expression of aromatase in prostate stromal cells. Here we show that PGE2 also up-regulates the expression of ERRalpha, which, as a transcription factor, further mediates the regulatory effects of PGE2 on the expression of aromatase. ERRalpha expression was up-regulated by PGE2 in prostate stromal cell line WPMY-1, which was mediated mainly through the protein kinase A signaling pathway by PGE2 receptor EP2. Suppression of ERRalpha activity by chlordane (an antagonist of ERRalpha) or small interfering RNA knockdown of ERRalpha blocked the increase of expression and promoter activity of aromatase induced by PGE2. Overexpression of ERRalpha significantly increased aromatase expression and promoter activity, which were further augmented by PGE2. Chromatin immunoprecipitation assay demonstrated that ERRalpha directly bound to the aromatase promoter in vivo, and PGE2 enhanced the recruitment of ERRalpha and promoted transcriptional regulatory effects on aromatase expression in WPMY-1. 17Beta-estradiol concentration in WPMY-1 medium was up-regulated by ERRalpha expression, and that was further increased by PGE2. Our results provided evidence that ERRalpha contributed to local estrogen production by up-regulating aromatase expression in response to PGE2 and provided further insights into the potential role of ERRalpha in estrogen-related prostatic diseases.
Molecular Endocrinology 03/2010; 24(6):1175-86. · 4.54 Impact Factor
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Longxin Wang,
Weihong Wen,
Jianlin Yuan,
Brian Helfand,
Yu Li,
Changhong Shi,
Feng Tian,
Jia Zheng,
Fuli Wang,
Lin Chen,
Lili Liang,
Liqun Zhou, Chung Lee,
Zhinan Chen,
Yinglu Guo,
He Wang,
Qiang Zhang,
Weijun Qin
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ABSTRACT: Transforming growth factor-beta (TGF-beta) is a potent immunosuppressor that has been associated with tumor evasion from the host immune surveillance and, thus, tumor progression. We tested a novel immunotherapy for human renal cell cancer (RCC) using a technique that involves the adoptive transfer of autologous tumor-reactive, TGF-beta-insensitive CD8(+) T cells into human RCC-challenged immunodeficient mice to identify its potent antitumor responses.
The present study was conducted using a one-to-one adoptive transfer strategy to treat tumor-bearing severe combined immunodeficient (SCID/beige) mouse. The SCID/beige mice were humanized with peripheral blood mononuclear cells from patients with RCC (Hu-PBMC-SCID) before adoptive transfer. Autologous CD8(+) T cells were expanded ex vivo using autologous patient's dendritic cells pulsed with the tumor lysate and rendered TGF-beta insensitive by dominant-negative TGF-beta type II receptor. In addition, human RCC cell lines were generated using patients' tumor cells injected into SCID/beige mice.
Using flow cytometry analysis, we confirmed the expression of the tumor-reactive, TGF-beta-insensitive CD8(+) T cells were the effector CD8(+) cells (CD27(-)CDRA(+)). Adoptive transfer of autologous TGF-beta-insensitive CD8(+) T cells into tumor-bearing Hu-PBMC-SCID mice induced robust tumor-specific CTL responses in vitro, were associated with tumor apoptosis, suppressed lung metastasis, and prolonged survival times in vivo.
The one-to-one adoptive transfer strategy is an ideal in vivo murine model for studying the relationship between TGF-beta and immunosurveillance in RCC in vivo. Furthermore, this technique may offer the promise of a novel therapeutic option for the treatment of human patients with RCC.
Clinical Cancer Research 12/2009; 16(1):164-73. · 7.74 Impact Factor
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ABSTRACT: Stromal smooth muscle cells (SMCs) play an important role in the pathogenesis and clinical symptom of benign prostatic hyperplasia. We had reported that estrogen enhances the phenotype of SMC in cultured prostate stromal cells (PRSCs). Here we further investigate the mechanism by which estrogen affects the differentiation of PRSCs.
Primary cultured PRSCs were stimulated with E2 or BSA-E2. The mRNA level of SMC-specific genes, smoothelin, and SM-MHC were measured by qRT-PCR. The SM-MHC protein was measured by Western blot. The mRNA and protein levels of TGF-beta1 were measured by qRT-PCR and ELISA. The MAPK inhibitor PD98059, the estrogen receptor antagonist ICI182,780 and neutralizing antibody to TGF-beta1 were used to reveal the mechanism of estrogen effect.
E2 and BSA-E2 significantly up-regulate the expression of SMC-specific genes in PRSCs. Both forms of estrogen could increase the expression of TGF-beta1, which can be blocked by pre-treating with PD98059. Moreover, PD98059 and TGF-beta1 neutralizing antibody could abrogate the effect of BSA-E2 on cell differentiation. However, they could only inhibit part of E2-induced SMC phenotype enhancement. ICI182,780 could partially suppress the pro-differentiation effect of E2 but had no influence on the effect of BSA-E2. Combined treatment with ICI182,780 and PD98059 can completely abrogate the effect of E2.
Estrogen could promote the expression of TGF-beta1 in PRSCs through nongenomic activation of MAPK pathway, and in turn enhance the SMC phenotype. Besides for this nongenomic effect, estrogen can also enhance the SMC phenotype through classical genomic action.
The Prostate 10/2009; 70(3):317-32. · 3.48 Impact Factor
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ABSTRACT: The aim of this study was to identify differential responses to low concentrations of 17beta-estradiol (E2) in primary stromal cell cultures derived from either normal organ donors or benign prostatic hyperplasia or hypertrophy (BPH) specimens. Furthermore, we sought to identify the potential mechanism of E2 action in these cell types, through either a genomic or nongenomic mechanism. We initially treated stromal cells derived from five normal prostates or five BPH specimens with low concentrations of E2 (0.001-1.0 nM) and analyzed their growth response. To determine whether genomic or nongenomic pathways were involved, we performed studies using specific estrogen receptor antagonists to confirm transcriptional activity or MAPK inhibitors to confirm the involvement of rapid signaling. Results of these studies revealed a fundamental difference in the mechanism of the response to E2. In normal cells, we found that a nongenomic, rapid E2 signaling pathway is predominantly involved, mediated by G protein-coupled receptor-30 and the subsequent activation of ERK1/2. In BPH-derived prostate stromal cells, a genomic pathway is predominantly involved because the addition of ICI 182780 was sufficient to abrogate any estrogenic effects. In conclusion, prostate stromal cells respond to far lower concentrations of E2 than previously recognized or examined, and this response is mediated through two distinct mechanisms, depending on its origin. This may provide the basis for new insights into the causes of, and possible treatments for, BPH.
Endocrinology 08/2009; 150(10):4594-605. · 4.46 Impact Factor
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ABSTRACT: It is known that human benign prostatic hyperplasia might arise from an estrogen/androgen (E/T) imbalance. We studied the response of castrated rat prostate to different ratios of circulating E/T. The castrated male Wistar rats were randomly injected with E/T at different ratios for 4 weeks. The prostates of E/T (1:100) group showed a distinct prostatic hyperplasia response by prostatic index, hematoxylin and eosin staining, and quantitative immunohistochemical analysis of alpha-smooth muscle actin (SMA). In this group, cells positive for Vimentin, non-muscle myosin heavy chain (NMMHC) and proliferating cell nuclear antigen (PCNA) increased in the stroma and epithelium. Furthermore, the mRNA levels of smooth muscle myosin heavy chain (SMMHC) and NMMHC increased. So E/T at a ratio of 1:100 can induce a stromal hyperplastic response in the prostate of castrated rats. The main change observed was an increase of smooth muscle cells, whereas some epithelial changes were also seen in the rat prostates.
Asian Journal of Andrology 07/2009; 11(4):451-9. · 1.52 Impact Factor
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Qiang Zhang,
Brian T Helfand,
Thomas L Jang,
Lihua J Zhu,
Lin Chen,
Ximing J Yang,
James Kozlowski,
Norm Smith,
Shilajit D Kundu,
Guangyu Yang,
Adekunle A Raji,
Borko Javonovic,
Michael Pins,
Paul Lindholm,
Yinglu Guo,
William J Catalona, Chung Lee
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ABSTRACT: Transforming growth factor-beta (TGF-beta)-mediated epithelial-to-mesenchymal transition (EMT) has been shown to occur in some cancers; however, the pathway remains controversial and varies with different cancers. In addition, the mechanisms by which TGF-beta and the EMT contribute to prostate cancer recurrence are largely unknown. In this study, we elucidated TGF-beta-mediated EMT as a predictor of disease recurrence after therapy for prostate cancer, which has not been reported before.
We analyzed TGF-beta-induced EMT using nuclear factor-kappaB (NF-kappaB) as an intermediate mediator in prostate cancer cell lines. A total of 287 radical prostatectomy specimens were evaluated using immunohistochemistry in a high-throughput tissue microarray analysis. Levels of TGF-beta signaling components and EMT-related factors were analyzed using specific antibodies. Results were expressed as the percentage of cancer cells that stained positive for a given antibody and were correlated with disease recurrence rates at a mean of 7 years following radical prostatectomy.
In prostate cancer cell lines, TGF-beta-induced EMT was mediated by NF-kappaB signaling. Blockade of NF-kappaB or TGF-beta signaling resulted in abrogation of vimentin expression and inhibition of the invasive capability of these cells. There was high risk of biochemical recurrence associated with tumors that displayed high levels of expression of TGF-beta1, vimentin, and NF-kappaB and low level of cytokeratin 18. This was particularly true for vimentin, which is independent of patients' Gleason score.
The detection of NF-kappaB-mediated TGF-beta-induced EMT in primary tumors predicts disease recurrence in prostate cancer patients following radical prostatectomy. The changes in TGF-beta signaling and EMT-related factors provide novel molecular markers that may predict prostate cancer outcomes following treatment.
Clinical Cancer Research 06/2009; 15(10):3557-67. · 7.74 Impact Factor
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Weijun Qin,
Feng Tian,
Fuli Wang,
Bin Song,
He Wang,
Qiang Zhang,
Borko Jovanovic,
Lili Liang,
Yinglu Guo,
Norm Smith, Chung Lee
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ABSTRACT: To test, using a mouse renal cancer, Renca, whether adoptive transfer of tumor-reactive transforming growth factor (TGF)-beta-insensitive cytolytic T cells can inhibit tumor progression.
Cytolytic T cells were isolated from the spleen of male Balb/c mice repeatedly primed with irradiated Renca cells. They were expanded ex vivo and were rendered TGF-beta-insensitive by infecting with a retrovirus containing dominant negative TGF-beta type II receptor.
These tumor reactive TGF-beta-insensitive cytolytic T cells showed a specific and robust tumor killing activity against Renca cells, but not irrelevant cells, using an in vitro cytotoxic assay. Adoptive transfer of cytolytic T cells was performed in mice 10 days after they were challenged with Renca cells (5 x 10(5)) by tail vein injection. At 30 days after the adoptive transfer, the pulmonary tumor counts in mice who had received TGF-beta-insensitive cytolytic T cells (mean +/- standard deviation 130 +/- 140) was significantly less than those in mice that had received TGF-beta-sensitive cytolytic T cells (305 +/- 60) or in mice had received naive cytolytic T cells (375 +/- 50; P < .01). Kaplan-Meier survival analysis indicated that mice that had received adoptive transfer of TGF-beta-insensitive cytolytic T cells had a significantly greater rate of survival (75%) compared with mice that had received TGF-beta-sensitive cytolytic T cells (35%) or naive cytolytic T cells (15%), respectively (P < .05).
These results suggest that adoptive transfer of tumor-reactive TGF-beta-insensitive cytolytic T cells can warrant consideration for renal cell cancer immunotherapy.
Urology 09/2008; 72(4):943-7. · 2.43 Impact Factor
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Feng Tian,
Longxin Wang,
Weijun Qin,
Fuli Wang,
Bin Song,
Yu Li,
Weihong Wen,
Zheng Zhang,
Kaichang Zhu,
Qiang Zhang, Chung Lee,
Weide Zhong,
Yinglu Guo,
He Wang
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ABSTRACT: Dendritic cells (DCs) have been widely used as cancer vaccines. However, their functional abilities have often been suppressed by tumor-secreted immunosuppressants such as transforming growth factor-beta (TGF-beta). We developed a new strategy using a TGF-beta insensitive DC as cancer vaccine. The effect of this vaccine was tested in a murine pulmonary metastases model of renal carcinoma (Renca). Tumor lysate-pulsed DCs (TP-DCs) were infected with retrovirus containing gene of dominant negative TGF-beta type II receptor (TbetaRIIDN) and thus made TGF-beta insensitive. Vaccination of the mice bearing Renca pulmonary metastases with the TbetaRIIDN TP-DC induced powerful tumor-specific cytotoxic T lymphocyte (CTL) responses, suppressed pulmonary metastases, and prolonged survival times. These results suggest TGF-beta-insensitive TP-DC vaccine can be used to enhance the antitumor efficacy of DC vaccine.
Cancer letters 08/2008; 271(2):333-41. · 4.86 Impact Factor
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Kent Perry,
Larry Wong,
Victoria Liu,
Irwin Park,
Qiang Zhang,
Varun Rejen,
Xuemei Huang,
Norm D. Smith,
Borko Jovanovic,
Scott Lonning,
Beverly A. Teicher, Chung Lee
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ABSTRACT: ObjectivesThe mouse renal cell carcinoma line, Renca, is insensitive to transforming growth factor-beta (TGF-β) in vitro. The present study was conducted to determine whether removal of TGF-β from these tumor cells would inhibit tumor progression in vivo.MethodsTGF-β elimination was accomplished either by administration of neutralizing TGF-β antibody into mice receiving intravenous injection of Renca tumor cells or infection of TGF-β antisense expression vector into these tumor cells before subcutaneous injection into recipient mice.ResultsAlthough a low dose of TGF-β antibody (5 mg/kg every 3 days) was without any effect, a high dose of TGF-β antibody (50 mg/kg every 3 days), administered to recipient mice, resulted in a significant reduction in lung metastasis and was accompanied by increased apoptosis in the tumor cells. When the tumor cells were transfected with a TGF-β1 antisense expressing vector, a significant reduction occurred in the tumor incidence, as well as the tumor burden. However, in nude mice, cells with reduced TGF-β1 production grew almost as well as did the unmodified Renca cells, suggesting that the host's immune system might play an antitumor role.ConclusionsThese results indicate that progression of Renca tumor can be inhibited by eliminating TGF-β from the tumor cells. Our results also suggest that, although insensitive to TGF-β under in vitro conditions, Renca tumors could be inhibited by TGF-β removal through the systemic host environment.
Urology 08/2008; · 2.43 Impact Factor
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ABSTRACT: Estrogen is involved in the development and progression of benign prostatic hyperplasia (BPH). It can stimulate proliferation of prostate stromal cells (PrSCs). However, the exact mechanism remains unclear.
We used the primary cultured human PrSCs and a prostate stromal cell line, WPMY-1, to examine the signaling pathways involved in estrogen-mediated proliferation of PrSCs. Cells were treated with 17beta-estradiol (E(2)) or BSA-E(2). Cell proliferation was assessed by the MTT assay and by cell counting. Western blot analysis was used to determine the status of activation of ERK1/2.
Results indicated that both E(2) and BSA-E(2) stimulated proliferation of primary PrSCs and WPMY-1 cells. ERK was rapidly activated by E(2) and BSA-E(2). PD98059, which is a selective ERK inhibitor, significantly inhibited estrogen-induced cell proliferation. PrSCs expressed estrogen receptor alpha (ERalpha) and GPR30 but not ERbeta. Small hairpin RNA (shRNA) to ERalpha, but not to GPR30, blocked estrogen-mediated ERK activation and cell proliferation.
The results indicated that estrogen could activate ERK pathway through the non-genomic ERalpha pathway, leading to proliferation of PrSCs.
The Prostate 05/2008; 68(5):508-16. · 3.48 Impact Factor
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ABSTRACT: The peripheral induction of T regulatory cells can be accomplished by TGF-beta through an epigenetic regulation leading to the expression of Foxp3. However, the exact mechanism of such a TGF-beta-mediated action remains unclear. In the current study, we found that TGF-beta treatment of CD4+CD25- T cells during T cell activation led to a transient inhibition of the phosphorylation of ERK followed by the induction of Foxp3 expression in these cells. Direct treatment with a specific ERK inhibitor, UO126, during CD4+CD25- T cell activation also induced Foxp3 expression and conferred a suppressive function to the induced Foxp3+ T cells. Furthermore, treatment of T cells with either TGF-beta or UO126 significantly down-regulated the expression of DNMTs, a reaction normally elicited by demethylation agents, such as 5-Aza-2'-deoxycytidine. These results indicate that the epigenetic regulation of TGF-beta-induced expression of Foxp3 may be mediated through the inactivation of ERK.
The Journal of Immunology 04/2008; 180(5):2757-61. · 5.79 Impact Factor
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ABSTRACT: To characterize a paracrine effect of prostatic epithelial cells in the presence or absence of oestradiol on the differentiation and proliferation of prostatic stromal cells.
Conditioned media (CM) collected from a prostatic epithelial cell line (BPH-1), which was pre-treated with different concentration of oestradiol, were added to cultures of primary prostatic stromal cells. The proliferation rates of stromal cells were determined using a tetrazolium assay. The mRNA level was analysed by real-time reverse transcription-polymerase chain reaction (RT-PCR), and the protein level of smooth muscle myosin heavy chain (SM-MHC), fibronectin and collagen IV were determined with Western blotting, enzyme- linked immunosorbent assay and radioimmunoassay, respectively. The expression of transforming growth factor beta1 (TGF beta 1) in the BPH-1 cell line was analysed.
The rate of proliferation of stromal cells increased when they were cultured with CM harvested from oestradiol-treated BPH-1 cells, but there was no remarkable change when they were cultured with CM from untreated cells. The level of smoothelin mRNA and SM-MHC protein increased after treatment with CM from BPH-1. The CM from BPH-1 with oestradiol stimulation was more effective in stimulating smoothelin mRNA and SM-MHC protein level. The protein level of collagen type IV, but not fibronectin, was up-regulated in the supernatants and cell extracts of CM-treated stromal cells. Oestradiol enhanced the expression and secretion of TGF beta 1 in BPH-1 cells. TGF beta 1-neutralizing antibody abrogated the effect of BPH-1 CM on the synthesis of collagen IV and SM-MHC in stromal cells.
These results suggest that oestradiol-stimulated proliferation and differentiation of prostatic stromal cells could be regulated by factors secreted from prostatic epithelial cells.
BJU International 03/2008; 101(4):497-502. · 2.84 Impact Factor
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ABSTRACT: Inflammation and infection have been linked to the pathogenesis of many cancers including prostate cancer. Components of bacteria and viruses have been identified within pathological specimens of men with prostate cancer.
We characterized the in vitro response of benign prostate epithelial cells to components of infectious agents as they relate to toll-like receptors.
Primary and immortalized prostate epithelial cells (RWPE) exhibited increased proliferation in response to exposure to lipopolysaccharide (LPS) and CpG DNA. These molecules are well-characterized surrogates for gram negative bacteria (e.g., E. coli) and DNA viruses (e.g., HPV and HSV), which are common in the genitourinary system. Our experiments show that RWPE cells express both TLR 4 (LPS-specific) and TLR 9 (CpG-specific). Targeted knock down of individual TLR expression using siRNA abrogated the proliferative response of RWPE cells to LPS and CpG, respectively. In addition, compared to non-stimulated cells, LPS and CpG up-regulate active NF-kB expression. Increased NF-kB activation was confirmed using RWPE cells that were stably transfected with a NF-kB reporter construct. Interestingly, NF-kB activation was both concentration- and time-dependent when stimulated with LPS. RWPE cells were less susceptible to TNF-alpha induced apoptosis as measured by TUNEL staining when stimulated with CpG or LPS. High concentrations of LPS also prevented cell death as measured by LDH release.
Our study has identified a unique mechanism that describes how components of pathogens common in the urinary system may contribute to the malignant transformation of benign prostate epithelia.
The Prostate 03/2008; 68(2):223-9. · 3.48 Impact Factor
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ABSTRACT: Dendritic cells (DCs) are highly potent initiators of the immune response, but DC effector functions are often inhibited by immunosuppressants such as transforming growth factor beta (TGF-beta). The present study was conducted to develop a treatment strategy for prostate cancer using a TGF-beta-insensitive DC vaccine. Tumor lysate-pulsed DCs were rendered TGF-beta insensitive by dominant-negative TGF-beta type II receptor (TbetaRIIDN), leading to the blockade of TGF-beta signals to members of the Smad family, which are the principal cytoplasmic intermediates involved in the transduction of signals from TGF-beta receptors to the nucleus. Expression of TbetaRIIDN did not affect the phenotype of transduced DCs. Phosphorylated Smad-2 was undetectable and expression of surface co-stimulatory molecules (CD80/CD86) were upregulated in TbetaRIIDN DCs after antigen and TGF-beta1 stimulation. Vaccination of C57BL/6 tumor-bearing mice with the TbetaRIIDN DC vaccine induced potent tumor-specific cytotoxic T lymphocyte responses against TRAMP-C2 tumors, increased serum IFN-gamma and IL-12 level, inhibited tumor growth and increased mouse survival. Furthermore, complete tumor regression occurred in two vaccinated mice. These results demonstrate that blocking TGF-beta signals in DC enhances the efficacy of DC-based vaccines.
Cancer Immunology and Immunotherapy 12/2007; 56(11):1785-93. · 3.70 Impact Factor
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ABSTRACT: Estradiol (E2) level in stroma of benign prostatic hyperplasia (BPH) increases with age, and this increase was associated with an elevated expression of aromatase in prostatic stromal cells (PrSCs). Here, we showed that conditioned medium (CM) of BPH-1 (a benign hyperplastic prostatic epithelial cell line), but not of prostate cancer cell lines (LNCaP, DU-145, and PC-3), stimulates aromatase expression in PrSCs. Cyclooxygenase-2 (COX-2) mRNA level in BPH-1, as well as prostaglandin E2 (PGE2) concentration in BPH-1 CM, was significantly higher than that of prostate cancer cell lines. CM of BPH-1 treated with NS-398 (a specific inhibitor of COX-2) failed to stimulate aromatase expression in PrSCs. And PGE2 can stimulate aromatase expression in PrSCs. Our data suggested that BPH-1 induced aromatase expression in PrSCs through the production of PGE2 in a paracrine mechanism.
Journal of Endocrinology 11/2007; 195(1):89-94. · 3.55 Impact Factor
